Bacterial contamination and endotoxin production in the water treatment system for hemodialysis

ABSTRACT

The present study aimed to assess bacterial contamination and endotoxin production in water treatment system for hemodialysis. It also aimed to evaluate the efficiency of decontamination measures applied along the water pathway in the system. The study was conducted in the water treatment system of Pediatric Dialysis Unit, Children's Hospital, Ain-Shams University. Samples were examined for four consecutive weeks after changing the bacterial filter; three samples were collected at each week. One sample was taken from tap water [sample A], another sample was taken from treated water just after the bacterial filter [sample B] and the third sample was taken from water in the returning pipe system not used by the hemodialysis machines [sample C]. Quantitative methods were used for the total count of viable heterotrophic microorganisms [denoting bacterial contamination], total coliforms, fecal coliforms, Enterococci, Pseudomonas spp. and the sulfite-reducing Clostridia [denoting fecal contamination]. The samples were assayed for endotoxin by the limulus amebocyte lysate [LAL] kit, employing a GEL-CLOT LAL. It is a qualitative non-kinetic assay